3D Selection Vault

Offset-Ray-Casting

In handheld AR, a screen cursor appears offset from the finger so the finger does not hide it, a swipe moves the cursor, and lifting the finger casts the ray and selects.

How it works

Touching places a cursor above the touch point; sliding moves the cursor with the offset kept, and the ray is cast from the camera through the cursor when the finger lifts. It reduces finger occlusion but does not help with objects hidden behind others. On an iPhone 6 with 12 participants (targets 0.2–1 cm, 20–80% occluded), error rates were 0.25% for PR-Bubble-Cursor, 1.2% for PR-Cone-Casting, 2.7% for touch Go-Go, 4.4% for 2D-Grid-Cursor, 5% for Offset-Ray-Casting and 41% for touch raycasting; times were 0.44 s for raycasting, 0.68 s PR-Cone, 1.22 s Offset, 1.29 s PR-Bubble, 2.06 s Grid and 2.75 s Go-Go. PR-Bubble-Cursor was preferred.

Papers

• Jibin Yin, Chengyao Fu, Xiangliang Zhang, Tao Liu (2019). Precise Target Selection Techniques in Handheld Augmented Reality Interfaces. IEEE Access 7, 17663-17674 doi:10.1109/ACCESS.2019.2895219
• Becky Spittle, Maite Frutos-Pascual, Chris Creed, Ian Williams (2023). A Review of Interaction Techniques for Immersive Environments. IEEE Transactions on Visualization and Computer Graphics doi:10.1109/tvcg.2022.3174805